Dust-band for watches



(No Model.) D. H. CHURCH.

DUST BAND POR WATCHES. No. 396,267. Patented Jam. l5, 1889.

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UNITED STATES PATENT GEETCE.

DUANE H. CHURCH, OF NEYTON, )LSSACHVSE'I' DUST-BAND FOR WATCHES.

SPECIFICATION forming part of Letters Patent No. 396,267, dated January 15, 1889. Application filed June 23, 1888. Serial No. 277,988. (No model.)

To all whom t may concern:

Be it known that I, DUANE H. CHURCH, of

Newton, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Dust-Bands for lVatehes, of which the followingl is a specilit-hat their proper and accurate action demands that they shall be free from disturbing influence. As ordinarily inclosed in cases of silver or gold for pocket use, it has been found almost impossible to exclude dust, and it frequently happens that quite large particles find their way through the joints of the case and lodge on some part of the movement.

It has been found practicable to protect the form otl movement commonly known as the full plate by an encirclingI band of metal, which closes the space between the top and pillar plates and prevents access to the train. The construction of the form of movement known as the three-quarter plate is such that heretofore no effective way has been found to apply a dust-band thereto.

lt is practically impossible to manufacture cases in quantities with the accuracy necessary to allow the pillar-plate of the watchthe case-center and the opposite vflange of the case-center to make a practically dust-proof joint with the top (or smaller diameter) edge of the dust-band when the latter is made in the ordinary way. To do this would require absolute accuracy in distance between the plate-shoulder and the opposite flange of the case-center and in the width of the dust-band. In full-plate movement and cases an opening at this place-viz., between the edge of dustband and the vflange of the case-eenter-is of little consequence if the top edge of the dustband fits the top plate of the movement; but in three-quarter-plate movements such an opening renders the dust-band useless, as at some portion of the diameter the top plate is broken (as indicated by the technical name three-quarter plate) and the openingis directly into the space between the two plates of the movement.

The object of my invention is to provide a dust-band that. shall be applicable to either of the above-named forms oli' movement, but more especially to the three-quarter plate, and shall not only serve to protect the sides or edge of a movement, but shall also close the space between the pillar-plate oli' the moveshown in Fig. l. movement to rest upon the plate-shoulder of ment and the inwardly-projecting flange at the opposite side ol the case-center.

)Iy improved dust-band is so constructed as to enable it to adjust itseltI to the inevitable slight variations in cases, so that while the movement is held rigidly to one ot the internal flanges ot' the case-center and rests on the plate-shoulder tlua'eotI the dust-band adjusts itself to the inner surface ot' the other flange of the case-center and insures a tight joint thereat, all ot which l will now proceed to describe and claim.

Oi' the accompanying drawings, forming a part ot' this specification, Figure .l represents a plan otl a case-center containing a threequarter-plate movement. lfig. 2 represents a section ot' the case-center, showing the movementas ordinarilyY mounted. Fig. Il represents a similar section showing the application of my improved dust-band. Fig. Jr represents an enlargenu-ait ot' a part ot' Fig. il. Fig. -l is a modification ol.' the ctmstruction Fig. represents a side view of a part ot' the dust-band. Fig. 3 represents a perspective view ot' the entire dust-lmnd. Figs. T, S, .l, ltl, and ll represent moditications of the dust-bami.

The same letters ot reference indicate the same parts in all the iigures.

In the drawings, a represents thc top plate of a three-quarter-plate movement, and b represents the opposite or pillar plate, the latter having the usual outwardly-projcctingshoulder, D.

c represents the watch-case center, having the usual flange or seat, c, t'or the shoulder 1) ot' the pillar-plate, and the inwardly-projecting flange d, which bears against the margin ot' the top plate.

e represents the dust-band, which is a ria;` of comparatively thin sheet metal formed at one edge to inclose and closely tit the periphery of the pillar-plate above the shoulder b thereof, and formed with an inwardly-pro- IOO jecting beveled flange, e, which contracts the diameter of its other edge nearly to that of the top plate.

To insure a close fit of the beveled or contracted edge of the dust-band against the flange d of the case-center, I provide means whereby continuous edgewise pressure is exertedon the dust-band to press the beveled portion thereof against the case-center flange.A Said pressure is best caused by springs 7L on the dust-band, arranged to bear on the pillarplate, and thereby hold the beveled portion of the dust-band with a yielding pressure against the flange. Said springs are preferably integral with the dust-band and formed by cutting into the band, as shown in Figs. 5 and G, to form tongues, and bending said tongues downwardly below the plane of the edge of the band that encircles the pillarplate, the springs thus formed being thus adapted to bear on the shoulder b of the pillar-plate. The springs 7L are so arranged that when the movement to which the dust-band is appliedis being inserted in a case-center the edge of the beveled flange e comes in contact with the flange d of the case-center before the pillar-plate colnes to a bearing on the seat c, so that the springs are deflected from their normal positions-and put under tension when the movement is fully inserted; hence the springs thereafter exert a continuous edgewise pressure on the dust -band, whereby its beveled portion is kept in close contact with the flange d of the case-center.

In Fig. a I have shown the under surface of the flange (l as substantially flat or horizontal instead of beveled, as represented in the other figures.

In Figs. 7, S, 9, and 10 I have shown the springs formed by cutting vertical slits in the band and bending inwardly the angles formed by cutting said slits. rlhe inwardlybent portions constitute the springs and bear against a beveled seat, t', Fig. 7, formed on the pi llar-plate. Then the movement ls inserted in the case-center, the pressure of said springs against the beveled seat i tends to straighten out the springs, as shown in Fig. 7, and in their effort to resume their normal position the springs, pressin inwardly on the inclined seat fz', will force the dust-band upwardly against the flange.

Fig. il shows a spring, 7L, formed by cutting two vertical slits and bending inwardly the tongue thus formed. The springs h may be made in separate pieces riveted or otherwise secured to the band e..

It is obvious that various other modifications in the form and arrangement of devices whereby the band is` provided with an elastic seating or bearing may be adopted without departing from the spirit of my invention.

I do not limit myself io the location of the elastic seating or bearing on the body of the band. A series of elastic springs may be secured to the case-center, and may rest, for eX- ample, on the inner surface of the flange c', sait'l springs being arranged to support the dust-band and press it against the flange d; or a continuous yielding seat of rubber in the form of a ring or washer may be applied to the case-center for the same purpose, although the last-named expedient would not be so desirable as those before described, on account of the liability of the rubber to deteriorate and to tarnish the metal with which it comes in contact.

l. A dust-band for watches, having an elastic seating or bearing at one edge,whereb y a yielding pressure is imparted to the band when it is incased, as set forth.

2. A dust-band for watches, having an elastic seating or bearing at one edge and a beveled portion or flange at its other edge, as set forth.

3. A dust-band for watches, having elastic tongues or springs at one edge, as set forth.

et. A dust-band for watches, having elastic tongues or springs at one edge and a beveled surface or flange at the other edge, as set forth.

5. The combination of a watch-movement, a case having flanges c d, a dust-band surrounding the movement between the flanges of the case, and means whereby an edgewise pressure is imparted to the dust-band, as set forth.

6. The combination of a watch-movement, a case having flan ges c d, and a dust-band surrounding the movement between said flanges, and provided at one edge with elastic bearings or springs and at the other edge with an inclined portion or flange, which is pressed by said springs against the case-flange, as set forth.

In testimony whereof l h ave signed my name to this specification, in the presence of two subscribing witnesses, this 20th day of June, A. D. 1838.

DUANE H. CHURCH.

lllitnesses:

WM. R. WILLs, THos. W. DIKE.

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